26 replies to this topic

[AustinF1]

On a local college sports board I frequent, we have a very active F1 thread where a poster suggested reducing the floor space of F1 cars. I mentioned the floors could be limited to within 1 cm of the bodywork, just as an example. This would, of course have huge aero/downforce implications.

 

When did the floors become rectangular, and why?

[Nonesuch]

I'm seeing cars with narrowing sidepods over a flat floor in the mid 1980s. 

 

Ground effects were banned in 1983.

 

Not having studied the issue in detail; I'm suspecting there might be a connection here.

[Seanspeed]

I dont know for sure, but I imagine that the ground effects era had a pretty profound impact on how F1 teams saw and used floors.  In 1983, ground effects were banned and a mandatory flat undertray was required and in 1984 we started seeing the first iterations of ' rectangular floors' at the rears of the cars, but usually only in certain configurations.  Took a few years before this became the common configuration.  

[Kalmake]

Although the first flat floor rules champion was the arrow shaped Brabham, it was realized bigger floor was the way to go for that sweet efficient downforce.

 

Over decades packaging got narrower, so the floor was left sticking out more.

 

For 2017 chassis maximum width was increased by 20cm and the teams pretty much only widened the floor.

[johnmhinds]

Earliest example I can think of is the Toleman in 1984.

 

 

Some of the other teams started experimenting with extending out the floor near the rear wheel in 1985

 

[Kalmake]

McLaren MP4/1C was like that in 1983 already.

[amedeofelix]

I'm seeing cars with narrowing sidepods over a flat floor in the mid 1980s. 

 

Ground effects were banned in 1983.

 

Not having studied the issue in detail; I'm suspecting there might be a connection here.

 

Shaped underfloors were banned. They only thought they were banning 'ground effect', because that's exactly what the diffuser does. In fact I bet the loads generated by the diffusers have exceeded those obtained in the so-called 'ground effect' era.

[amedeofelix]

McLaren MP4/1C was like that in 1983 already.

 

Yup. The so-called Coke bottle is a Barnard baby. It got more extreme with his Ferrari in 1989.

[PayasYouRace]

On a local college sports board I frequent, we have a very active F1 thread where a poster suggested reducing the floor space of F1 cars. I mentioned the floors could be limited to within 1 cm of the bodywork, just as an example. This would, of course have huge aero/downforce implications.

 

When did the floors become rectangular, and why?

 

The short answer is that the maximum allowed floor area is defined rectangularly so the teams use it all. As a flat floor is mandated, the best way to produce downforce is with the largest floor area possible.

 

What has happened since 1983 is that the bodywork above the floors has shrunk.

[amedeofelix]

On a local college sports board I frequent, we have a very active F1 thread where a poster suggested reducing the floor space of F1 cars. I mentioned the floors could be limited to within 1 cm of the bodywork, just as an example. This would, of course have huge aero/downforce implications.

 

When did the floors become rectangular, and why?

As I said elsewhere reducing the floor area would be retrograde as the 'ground effect' of the diffuser fed by the floor is not affected the way wings are when one car follows another. Want less aero grip? OK, but do so by restrictions on the wings not the floor. What's more important that the car looks how you find it attractive or that the cars are able to race one another?

Edited by amedeofelix, 23 February 2018 - 15:44.

[PayasYouRace]

As I said elsewhere reducing the floor area would be retrograde as the 'ground effect' of the diffuser fed by the floor is not affected the way wings are when one car follows another. Want less aero grip? OK, but do so by restrictions on the wings not the floor. What's more important that the car looks how you find it attractive or that the cars are able to race one another?

 

Flat floors are much more sensitive than venturis when it comes to following in another car's wake.

[blackmme]

As Kalmake said it was the MP4/1C of 1983 that introduced it.

Regards Mike

[MadYarpen]

I wonder how would they look without this floor!

[AustinF1]

As I said elsewhere reducing the floor area would be retrograde as the 'ground effect' of the diffuser fed by the floor is not affected the way wings are when one car follows another. Want less aero grip? OK, but do so by restrictions on the wings not the floor. What's more important that the car looks how you find it attractive or that the cars are able to race one another?

Yeah, hadn't thought of that. I'm also of the opinion that F1 should be seeking more DF from the floor and less from the wings. 

[amedeofelix]

Another solution is to bring in, as I have suggested before, the same floor type Indy has used which has what they call 'Venturi tunnels', and then mandate that sidepods mate with the floor shape (not necessary but if it is deemed important for 'looks'). Then, also like Indy, limit the number of elements of the wings and maybe their 'cord' too.

Edited by amedeofelix, 23 February 2018 - 15:57.

[PedroDiCasttro]

Another solution is to bring in, as I have suggested before, the same floor type Indy has used which has what they call 'Venturi tunnels', and then mandate that sidepods mate with the floor shape (not necessary but if it is deemed important for 'looks'). Then, also like Indy, limit the number of elements of the wings and maybe their 'cord' too.

This here is the best solution. 

[V8 Fireworks]

Shaped underfloors were banned. They only thought they were banning 'ground effect', because that's exactly what the diffuser does. In fact I bet the loads generated by the diffusers have exceeded those obtained in the so-called 'ground effect' era.

 

Yes, and that is because the bargeboards via controlled vortices are used to enhance the aerodynamic effects of the flat floor, to make it;s performance surprass that (potentially) of a tunnel.

 

We've already discussed the Deltawing idea (sending a big counter rotating vortex pair through under the car, to energise the ground effects)  in the most beautiful Indycar thread, and I made a Flat floor + diffuser VS inverted wings thread here http://forums.autosp...ffects-is-best/

 

For reference, a Formula 2 car still uses something more similiar to a simple Venturi tunnel rather than a flat floor energized by vortices with lots of rake..

 

Formula 2 diffuser: venturi tunnel like

 

Formula 2, you can see the F2 venturi/diffuser starts well ahead of rear axle, unlike F1

 

Why make the flat floor as large as possible?  Simply it's the surface over which the low pressure (vacuum) underneath the car acts.  Bigger floor = more downforce (if a consistent low pressure can be created under the floor via the aerodynamic sealing using vortices generated by the barge-boards and so on).

 

Formula 1 underbody, pressure coefficient from racecar engineering magazine

 

 

Fancy underbody vortex structure (CART as an example)

 

 

William Toet discusses interesting upper body f1 aero considerations here too (basically push the wake of the fron t wheels outboard of the car, and minimise the air which is impinging on the rear wheels too)  https://www.linkedin...art-willem-toet

Edited by V8 Fireworks, 23 February 2018 - 16:25.

[V8 Fireworks]

Another solution is to bring in, as I have suggested before, the same floor type Indy has used which has what they call 'Venturi tunnels', and then mandate that sidepods mate with the floor shape (not necessary but if it is deemed important for 'looks'). Then, also like Indy, limit the number of elements of the wings and maybe their 'cord' too.

 

Good point.  Problem is F1 teams get more downforce by running rake, in effect increasing the angle of the diffuser and making the whole raked floor a diffuser.

 

You would HAVE TO clean up the complex front wings and bargeboards that allows the current raked floor to remain sealed aerodynamically, even though the cars are running lots of rake and there is a huge gap at the physical sides of the floor.

[amedeofelix]

Good point.  Problem is F1 teams get more downforce by running rake, in effect increasing the angle of the diffuser and making the whole raked floor a diffuser.

 

You would HAVE TO clean up the complex front wings and bargeboards that allows the current raked floor to remain sealed aerodynamically, even though the cars are running lots of rake and there is a huge gap at the physical sides of the floor.

 

If a shaped underfloor were brought in the rake becomes unnneded. It wasn't there before so...

[V8 Fireworks]

Shaped underfloors were banned. They only thought they were banning 'ground effect', because that's exactly what the diffuser does. In fact I bet the loads generated by the diffusers have exceeded those obtained in the so-called 'ground effect' era.

 

They have, primarily because the modern cars are designed with three-dimensional considerations, whereas the early venturi cars were simple 2D tunnels (not bad given the vastly different resources and technology available to design it, of course!).

[V8 Fireworks]

If a shaped underfloor were brought in the rake becomes unnneded. It wasn't there before so...

 

True.  But F2 and Indycar run tunnels because rules and yet they still make less downforce than F1.

 

They don't have rake because they are not setup for that, with the bargeboards and so on.

 

Given the chance, wouldn't F1 teams use rake * as well* and every means possible to get every bit of downforce? That's what F1 teams do, very different than designing a spec car based more on first principles and using modest resources.

Edited by V8 Fireworks, 23 February 2018 - 16:30.

[V8 Fireworks]

I wonder how would they look without this floor!

 

Better!

[amedeofelix]

True.  But F2 and Indycar run tunnels because rules and yet they still make less downforce than F1.

 

They don't have rake because they are not setup for that, with the bargeboards and so on.

 

Given the chance, wouldn't F1 teams use rake * as well* and every means possible to get every bit of downforce? That's what F1 teams do, very different than designing a spec car based more on first principles and using modest resources.

 

If it's useful to have rake I bet they'd still use it. My point is it doesn't matter to this point.

 

Yes Indy has less downforce, but those 'Venturi tunnels' are quite restricted in width. You could just allow them to be bigger. F1 doesn't have ovals to take into account after all so can generate much more downforce without 'issues' like having a car that can all of a sudden go the same speed around an oval corner as it does down the straightaway as my fellow Yanks like to call it.

[Nonesuch]

Shaped underfloors were banned. They only thought they were banning 'ground effect', because that's exactly what the diffuser does.

 
Right, good addition.    It's not technically correct - but this is the way it's commonly described in F1's history books.
 
I suppose it's a matter of convention trumping accuracy, leading to some ambiguity or even confusion.
 

As a flat floor is mandated, the best way to produce downforce is with the largest floor area possible.

 
I'm not sure which time is described, but currently the floor is not flat but rather stepped.
 
Article 3.7.1 of the Technical Regulations for 2018 describes it in some more detail:
 

With the parts referred to in Articles 3.7.10, 3.7.11 and 3.7.12 removed all sprung parts of the car situated from 430mm behind the front wheel centre line to 175mm in front of the rear wheel centre line, and which are visible from underneath, must form surfaces which lie on one of two parallel planes, the reference plane or the step plane. This does not apply to any parts of rear view mirrors which are visible, provided each of these areas does not exceed 16000mm² when projected to a horizontal plane above the car. The step plane must be 50mm above the reference plane.

[Kalmake]

Stepped floor started with 10mm wood plank in 1994.

[Thursday]

1983 Mclaren MP4/1C is the earliest I can think of. Other cars in '83 tended to have short sidepods with the BT/52 being the most extreme.

I had always thought the reason cars went back to having sidepods starting along side the driver instead of futher back was for side impact safety but perhaps it was to exploit the floor.

 

[PayasYouRace]

The sidepods moved forward to allow air round the wheels, as McLaren pioneered in 83. It has the added bonus of bringing the radiators near the centre of the car, lowering its rotational inertia and improving balance. Basically the BT52 solution was the worst arrangement, but its massive power advantage allowed it to win.

Putting crash structures in the sidepods came later.

And yes, for the pedantic, the current floors are stepped. The step is longitudinal, so has limited aero effect. It was introduced to keep more of the floor out of ground effect, and lower downforce.